SHANGHAI (BLOOMBERG, REUTERS) - Beijing’s daily Covid-19 cases are continuing to ebb, while outbreaks in other regions are coming under closer watch for clues on how authorities will respond to another major resurgence.  

The Chinese capital reported just one local case for Wednesday (June 8), the lowest number since April 21, a reclassification of an earlier asymptomatic infection to one causing symptoms.

It marks the fourth straight day of single digit cases, with life moving closer to normal as Covid restrictions are gradually loosened.

Shanghai, which reported nine cases for Wednesday, said it will lock down a south-western district on Saturday morning for mass Covid-19 testing.

Minhang, home to more than 2 million people, will conduct nucleic acid tests for all residents on June 11, and restrictions will be lifted once the testing is completed, the government said on its WeChat account. 

The mass test and lockdown plan are aimed at "consolidating the achievements of the city’s epidemic prevention and control, and dynamically discovering and controlling epidemic risks," according to a statement from the local health commission.

Elsewhere in the city of 25 million, officials also appear to be escalating curbs and placing compounds back under lockdown over the slightest hint of infection risk.

Some housing compounds in the central Jing’an and Xuhui districts were sealed for 14 days from Tuesday, although only close contacts – no confirmed cases – were found among residents.

In both districts, people in some affected areas are barred from leaving their homes and are subject to a daily Covid test, according to the latest policy.

Others will be quarantined for seven days, followed by another week of health monitoring at home. During the control period, all vehicles in regions except for buses and ambulance are banned, according to government statements.

Nationwide, China reported 164 infections for Wednesday.

While infections have dropped in the two cities, rising numbers in places like Dandong and Inner Mongolia – and the control measures that are being deployed – are coming under focus to see how far authorities will go to stamp out the virus.

Dandong residents living by the Yalu River that runs between China and North Korea have been asked to close their windows on days with southerly winds, raising suspicion that authorities are considering the possibility that the virus is being transmitted through the air from its neighbour.   

In Inner Mongolia, cases jumped on Wednesday to 130 from 81 the previous day.

The flareup there has centred on a border city Erenhot, the largest port city between China and Mongolia, which has been in lockdown for the past week.

Authorities started a dragnet operation there on Sunday aimed at checking every household to verify virus information and register residents.

Cases in Beijing, which used to be several dozen a day, have dropped since mass-testing and targeted measures such as movement restrictions and work-from-home orders were implemented in the worst affected areas.  

China has trumpeted its Covid Zero approach, which included an unprecedented two-month lockdown of Shanghai and harsh restrictions elsewhere, for bringing its outbreak under better control.

But its success has come at an enormous economic and social cost, and hasn’t totally eliminated infections.